Organophosphorus-copper complex compounds



United States Patent r 7 Claims. (Cl. 260-438.1)

This application is a division of our-copending application, Ser. No. 354,436, filed Mar. 24, 1964 now US. Patent No. 3,294,870.

This invention relates to a novel class of compounds. More particularly, this invention relates to a novel class of organophosphorous-copper complex compounds.

The search for compounds, mixtures of compounds or compositions of matter as flame-retardants for thermoplastic polymers has been intensively conducted industrially. The use of materials containing phosphorous and/ or nitrogen atoms as flame-retardant additives for some polymers has been recognized, as has been the use of various halogenated materials such as the halogenated styrene copolymers and various additive mixtures such as chlorinated parafiin Wax with triphenyl stibine, chlorinated parafiins with aliphatic antimony compounds, antimony-oxide-chlorinated hydrocarbon mixtures and the like. A drawback, however, in regard to the known prior art materials which have been used as flame-retardants, has been the fact that generally a large amount, i.e. upwards of 35%, of the additive must be incorporated into the polymer in order to make it sufliciently flame-retardant. Additionally, many of the known flame-retardant additives have a tendency to crystallize or oil out of the resin a relatively short time after incorporation.

We have now found a new group of compounds which may be used, by adding them to thermoplastic resins, in relatively small amounts, to produce excellent flameretardant compositions. A further feature of our invention resides in the fact that these newadditives do not crystallize or oil out after incorporation into the resin even after an extensive length of time.

The production of thermoplastic resin compositions which are flame-retardant, i.e. have high resistance to burning, is of considerable commercial importance. For example, such articles as castings, moldings, foamed or laminated structures and the like are required, or at least desired, to be resistant to fire and flame and to possess the ability to endure heat without deterioration. Typical illustrations of applications of materials of this type include moldings for live electrical contacts which should not be ignited or deteriorated by heat and sparks. Additionally, structural members such as pipes, Wall coverings, wall panelingglazing, etc. and articles such as ash trays, waste baskets, fibers and the like are further examples of products wherein flame retardance is desirable.

It is therefore an object of the present invention to provide a novel class of compounds.

It is a further object of the present invention to provide a novel class of organophosphorous-copper complex compounds.

These and other objects will become more apparent to those skilled in the art upon reading the more detailed description set forth hereinbelow.

THE NOVEL COMPOUNDS The novel organophosphorous-copper complex com pounds of the instant invention are represented by the formula wherein X is a monovalent anion and R is an aryl or a [i-cyanoethyl radical.

These compounds are solid in nature and have relatively high melting points, e.g., as high as 280 C. They are soluble in such organic solvents as benzene, toluene, chloroform and the like and are insoluble in diethyl ether, water, tetrahydrofuran and the like.

The compounds of Formula I may be produced, by reacting an ethylene-bis disubstituted phosphine with a copper salt, i.e. of the formula CuX. The reaction proceeds according to the equation:

wherein R and X are as set forth hereinabove in regard to Formula I. The ethylenebis disubstituted phosphine starting material can be produced according to any known procedure, that shown in an article by Chatt et al., J. Chem. Soc. L378, 1960, being exemplary.

The reaction is preferably carried out at room temperature and atmospheric pressure, although higher or lower temperatures and pressures may be used if circumstances so dictate. A solvent such as tetrahydrofuran, ethanol, aqueous potassium iodide and the like is used for both react-ants. The amount of solvent used is not critical, except that enough should be employed to carry out its function, i.e. to solubilize the reactant.

The reaction is generally allowed to continue for from about 10 minutes to 1 hour, preferably 20 to 40 minutes, however, this range is not critical and shorter or longer times of contact may be used, if necessary.

The molar ratio of the ethylenebis compound to the copper salt used is about 1:1 although a slight excess of either reactant is tolerable.

The products may be recovered by filtration, centrifugation, etc. and may then be further purified by recrystallization, non-solvent washing and the like.

Compounds which are represented by Formula I and which are useful in producing our novel flame-retardant compositions include:

[ethylenebis(diphenylphosphine) ]copper(I) iodide, [ethylenebis(ditolylphosphine)copper(I) iodide, [ethylenebis(dixylylphosphine) ]copper (I) iodide, [ethylenebis didurylphosphine) copper (I) iodide, [ethylenebis(di-l-naphthylphosphine)]copper(I) iodide, [ethylenebis(di-Z-naphthylphosphine) ]copper(I) iodide, {ethylenebis [bis (B-cyanoethyl) phosphine] }copper(I) iodide, [ethylenebis(diphenylphosphine)]copper(I) chloride [ethylenebis(ditolylphosphineflcopper(I) chloride, [ethylenebis(dixylylphosphine) ]copper(I) chloride, [ethylenebis didurylphosphine) copper(I) chloride, [ethylenebis( dil-naphthylphosphine) copper(I) chloride,

7 [ethylenebis (di-Z-naphthylphosphine) copper(I) chloride, {ethylenebis[bis (fl-cyanoethyl) phosphine] }copper(I) chloride, [ethylenebis(diphenylphosphine) copper(I) bromide, [ethylenebis(ditolylphosphine)]copper(1I) bromide, [ethylenebis(dixylylphosphine) ]copper(I) bromide, [ethylenebis(didurylphosphine) 1 copper(I) bromide, [ethylenebis(di-l-naphthylphosphine) copper(I) bromide, [ethylenebis (di-Z-naphthylphosphine) copper(I) bromide, {ethylenebis[bis(B-cyanoethyDphosphhre] }copper(I) bromide, [ethylenebis diphenylphosphine) copper (I) nitrate, [ethylenebis (ditolylphosphine) 1 copper (I) nitrate, [ethylenebis (dixylylphosphine) copper(I) nitrate, [ethylenebis(didurylphosphine) ]copper(I) nitrate, [ethylenebis (di-l-naphthylphosphine) copper(I) nitrate, [ethylenebis di-Z-naphthylphosphine) copper (I) nitrate, {ethylenebis [:bis (p-cyanoethyl) phosphine] }copper(I) nitrate, [ethylenebis diphenylphosphine) copper I) acetate, [ethylenebis (ditolylphosphine) ]copper (I) acetate, [ethylenebis (dixylylphosphine) copper(I) acetate, [ethylenebis didurylphosphine) copper (I) acetate, [ethylenebis(di-l-naphthylphosphine) copper(I) acetate, [ethylenebis(di-Z-naphthylphosphine) copper(I) acetate, {ethylenebis [bis(fi-cyanoethyl) phosphine] }copper(I) acetate, [ethylenebis diphenylphosphine) copper I) phenate, [ethylenebis (ditolylphosphine) copper (I) phenate, [ethylenebis(dixylylphosphine) ]copper(I) phenate, [ethylenebis(didurylphosphine) ]copper(I) phenate, [ethylenebis(di-l-naphthylphosphine) copper(I) phena-te, [ethylenebis (di-Z-naphthylphosphine) ]copper (I) phenate, {ethylenebis [bis( fi-cyanoethyl) phosphine] }copper I) phenate, [ethylenebis(diphenylphosphine) ]copper(I) benzoate, [ethylenebis(ditolylphosphine) copper( I) benzoate, [ethylenebis dixylylphosphine) copper (I benzoate, [ethylenebis didurylphosphine) ]copper( I) benzoate, [ethylenebis (di-l -naphthylphosphine) ]copper(I) benzoate,

I [ethylenebis( di-2-naphthylphosphine) copper( I) benzoate, {ethylenebis [bisQH-cyanoethyl)phosphine] }copper(I) benzoate, and the like.

THE NOVEL FLAME-RETARDANT COMPOSITIONS The thermoplastic polymers into which the novel compounds of our invention may be incorporated to produce the novel flame-retardant compositions of the present invention, are generally the vinyl type polymers wherein the monomeric material is polymerized, by any known method, via the vinyl unsaturation therein. Examples of the vinyl type polymers which may be used to form our novel compositions are the acrylates and methacrylates, the vinyl halides, the vinylidene halides, the 'vinyl acetates, polyvinyl butyral, butadiene copolymers, acrylonitrilebutadiene-styrene polymers, the acrylonitriles, etc. Additionally, and preferably, one may incorporate the flameretardant agents mentioned above into the a-olefin polymers, such as the homopolymers and copolymers, etc. containing, as the major constituent, ethylene, propylene, and the like and the acrylates and methacrylate polymers produced from monomers having the formula wherein R is a-hydrogen or methyl radical and R is a hydrogen or an alkyl radical having from 1 to 6 carbon atoms, inclusive. Examples of monomers represented by Formula II include acrylic acid, methacrylic acid and their esters such as methyl acrylate, ethyl acrylate, npropyl acrylate, isopropyl acrylate, n-butyl acrylate, tbutyl acrylate, isobutyl acrylate, n-amyl acrylate, t-amyl acrylate, hexyl acrylate, and the corresponding alkyl methacrylates.

Additional examples of monomers which may be'used to form the thermoplastic vinyl polymers'encompassed by the'present invention, polymerized either singularly or in combination with each other or with the other compounds set forth hereinabove, are such monomers as the unsaturated alcohol esters, more particularly, the allyl, methallyl, vinyl, methvinyl, butenyl, etc., unsaturated esters of aliphatic and aromatic monobasic acids, such, for instance, as acetic, propionic, butyric, crotonic, suc' cinic, glutaric, adipic, maleic, fumaric, itaconic, benzoic, phthal-ic, terephthalic, benzoylphthalic, etc., acids; the saturated monohydric alcohol esters, e.g., the methyl, propyl, ethyl, isopropyl, butyl, sec.-butyl, amyl, etc., esters of ethylenically unsaturated aliphatic monobasic acids, illustrative examples of which appear above, vinyl cyclic compounds (including monovinyl aromatic hydrocarbons), e.g., styrene, 0-, m-, and p-chlorostyrenes, -bromostyrenes, -fluorostyrenes, -methylstyrenes, -ethylstyrenes,--cyanostyrenes, the various poly-substituted styrenes such, for example, as the various di-, tri-, and tetrachlorostyrenes, -bromostyrenes, -fluorostyrenes, -methylstyrenes, .-ethylstyrenes, -cyanostyrenes, etc. vinyl pyridine, divinyl benzene, diallylbenzene, the various allyl cyanostyrenes, the various alpha-substituted styrenes and alpha-substituted ring-substituted styrenes, e.g., alphamethyl styrene, alpha-methyl-para-methyl styrene, etc.; unsaturated ethers, e.g., ethyl vinyl ether, diallyl ether, etc.; unsaturated amides, for instance, N-allyl caprolactam, acrylamide and N-substituted acrylam'ides, e.g., N-methylol acrylamide, N-allyl acrylamide, N-methyl acrylamide, N-phenyl acrylamide, etc.; unsaturated ketones, e.g., methyl vinyl ketone, methyl allyl ketone, etc.; methylene malonic esters, e.g., methylene methyl malonate, etc. and ethylene.

Other examples of monomers that can be used as polymers to form the resin portion of our novel flame-retardant compositions are the vinyl halides, more particularly, vinyl fluoride, vinyl chloride, vinyl bromide, and vinyl iodide, and the various vinylidene compounds, including the vinylidene halides, e.g., vinylidene chloride, vinylidene bromide, vinylidene fluoride, and vinylidene iodide, other comonomers being added, if needed, in order to improve the compatibility and copolymerization characteristics of the mixed monomers.

These above mentioned monomers may be polymerized, copolymerized, etc, in any known manner such as by free-radical generating catalysts, irradiation, anion and cation type catalysts and the like, said method of polymerization forming no part of the present invention.

The novelflame-retardant compounds may be incorporated into the thermoplastic resins in flame-retarding amounts, i.e. amounts generally ranging from about by weight, to about 35%, by weight, preferably to 25%, by. Weight, based on the weight of the resin have been found suflicient.

The organophosphorus-copper complex compounds may be incorporated into the resin by any known method. That is to say, the flame-retardant additive may be com- 6 pure compound having a melting point of 283-285 C.

Analysis.Calculated for C H P CuI: C, 53.03; H, 4.11; P, 10.52; Cu, 10.79; I, 21.55. Found: C, 52.83; H, 4.18; P, 9.97; Cu, 9.92; I, 19.85.

Following the procedure of Example 1, various ethylenebis disubstituted phosphines are reacted with cuprous salts to produce the corresponding organophosphoruscopper complex compounds. of the present invention. The results are set forth hereinbelow in Table I.

Any appropriate fiame-retardance test may be used to determine the flame-retardant properties of any specific composition of the present invention. One test which is reasonably efiicient is that designated as a modified version of ASTM test D-635-56T. The specifications for this bined with the resin by milling the resin and the flame 15 test are: a specimen, 5" in length, 0.5" in width and retardant complex on, for example, a two-roll mill, in a 0.045" in thickness, is marked at the 1" and 4" lengths Banbury mixer, etc., or the copper complex may be and is then supported with its longitudinal axis horizonadded by molding it and resin simultaneously, extruding it tal and its transverse axis inclined at 45 to the horizonand the resin or by merely blending the resin in powder tal. A Bunsen burner with a 1" blue flame is placed under form with the organophosphorus-eopper complex comthe free end of the strip and is adjusted so that the flame pound and thereafter forming the final desired article. tip is just in contact with the strip. At the end of 30 Additionally, the novel flame-retardant compounds may seconds, the flame is removed and the specimen is allowed also be added during the resin manufacture, i.e. during to burn. If the specimen does not continue to burn after the monomer polymerization procedure, provided the the first ignition it is immediately recontacted with the catalyst etc., and other ingredients of the polymerization burner for another v second period. If after the two system are inert thereto. burnings, the strip is not burned to the 4" mark, the

It is within the scope of the present invention to inspecimen is designated as self-extinguishing or flamecorporate such ingredients as plasticizers, dyes, pigments, retardant. fillers, stabilizers, antioxidants, antistatic agents and the Example 20 like to our novel compositions wlthout detractmg from 0 the advantageous properties thereof.

The following examples are set forth for purposes of Eighty Parts of P y y and 20 Parts Of illustration only and are not to be construed as limita- [ethylenebis(diphellylphosphifle)l pp iodide are tions on the present invention except as set forth in the rolled together on a two-r011 mill at about The appendgd c1aim5 parts and percentages are by weight resulting COIIlpOSltlOl'l is molded into strips 5" in unless otherwise specifiegi length, 0.5 and 0.045" ill thickness and Said strips are then subjected to an art-recognized flame-retardance test. The strips pass the test and are therefore Example 1 designated as flame retardant.

40 Following the procedure of Example 20, the following A solution of 4.0 parts of ethylenebis(diphenylphosexamples were carried out utilizing various flame retardphine) in 20 parts of ethanol and 50 parts of tetrahydroants of the instant invention and various thermoplastic furan are mixed all at once at room temperature with resin polymers. The results of these examples are set forth a solution of 1.9 parts of cuprous iodide in 30% aqueous in Table II, below. In each instance, the resultant comtetrahydrofuran containing 25 parts of potassium iodide. position passed the flame-retardance test and was desig- The precipitated product is filtered and washed with nated as flame and fire retardant. In the table, PE=polypotassium iodide solution, with water, and with tetrahyethylene, PAN=polyacrylonitrile, PP=polypropylene, drofuran. 5.4 parts of [ethylenebis(diphenylphosphine)]- PMMA=poly(methyl methacrylate), PMA=poly(methcopper(I) iodide are recovered (91.5% of theoretical). acrylic acid), PA=poly(acrylic acid), AN=acrylonitrile, Recrystallization from chloroform-diethylether gives a ST=styrene and BD=butadiene.

TABLE I Example Phosphine Cnspfigus T., 0 Product Ethylenebis(diphenylphosphine) 011B 23 [Ethylenebis(diphenylphosphineflcopper(I) bromide. do CuNOa 23 [Ethylenebls(d1phenylphosph1ne)]copper(I) nitrate.

do CuAc 23 [Ethylenebis(diphenylphosphine)]copper(I) acetate.

Ethylenebis[bis(;3-eyanoethyl)phosphine] CuPh 45 lEgtlylenebiswis(fl-cyanoethyDphosphine]lcopperfl) phen- Ethy[enebis(didurylphosphine) OuBz 23 [Ethylenebi s(didurylphosphinefleopper(I)benzoate. Ethylenebis(dixylylphosphine)A CuI 23 [Ethylenebls(dixylylphosphine)]copper(I) iodide. Ethylenebis(ditolylphosphine) C111 50 [Ethyleneb s(d tolylphosphine)]eopper(I) iodide. Ethylenebis(dixylylphosphine) OuBl 23 [Ethyleneb s(d1xylylphosph1ne)]copper(I) bromide. Ethylenebis(didurylphosphine) CuI 23 [Ethyleneb s(diduxylphosphineflcopper(I) iodlde. Ethylenebis(did'naphthylphosphine) CuNO 29 [Ethylenebis(di-l-naphthylphosphine)]-copper(1) nitrate. Ethylenebislbis(B-cyanoethyDphosphine] CuI 23 lliggygnebismis(fl-cyanoethybphosphine]}-copper(I) Ethylenebis(dixylylphosphine) 50 [Ethylenebis(dixylylphosphineflcopper(I) acetate. Ethylenebis(ditolylphosphine).. 45 [Ethylenebls(ditolylphosphine)]copper (I) phenate. Ethylenebis[bis(fl-cyanoethyl)phosp he 15 {litgirlsglbisfbis(,B-cyanoethyl)phosphine]}-eopper(I) Ethylenebis(ditolylpliosphine) 01101 3 [Ethylenebis(ditolylphosphine)]copper(I)chloride. Ethylenebis[bis (fl cyanoethyl) phosphine] CuAc 23 llitlggliiieiebiswis (fi-cyanoethyl) phosphine] }-eopper(I) Ethylenebislbis(fl-cyanoethyDphosphine] CuBr 30 {Eggyleaigbiswis(B-eyanoethybphosphlnc]}-eopper(1) Ethylenebis(di-Z-naphthylphosphine) CuPh 0 [Ethy fienebis(di-2-naphthylphosphine)]-copper(I) phenate.

Code for Table I: Ac=acetate; Ph=phenate; Bz=benzoate.-

TABLE II Flame- Retardant Ex. Resin $3E Percent InExample Number 1 15 6 10 1% 25 25 PAN- 12 30 10 Mixture of BD-AN (10-75%) and 8 25 ANS'I(25-90%).* Same as 26 1 25 Terpolymer MMA/ST/AN 71/19/10.. 4 20 E 3 20 7 25 6 25 1o 16 25 10 20 17 5 10 14 25 .2 as 15 20 18 2O 19 *U.S. Patent No. 2,439,202.

We claim: 25 1. A compound having the formula R l R-P CH2 \l CuX gr 7' R]? wherein X is a monovalent anion and R is selected from the groupconsisting of aryl and B-cyanoethyl radicals.

2. A-compound according to.claim 1 wherein R is a phenyl radical.

3. A compound according to claim 1 wherein X is chlorine.

4. A compound according to claim 1 whereinR is a phenyl radical and X is chlorine.

5. A compound according to claim 1 whereinRis a fl-cyanoethyl radical.

6. A compound according to claim -1 wherein X is a phenate.

7. A compound according to claim 1 wherein R is a ,B-cyanoethyl radical and X is a phenate.

References Cited UNITED STATES PATENTS 2,150,349 3/1939 Peski et al 260438.1 2,909,544 10/1959 Birum 260-4381 3,084,179 4/1963 Chatt et a1. 260-429 FOREIGN PATENTS 83 6,647 4/ 1952 Germany.

TOBIAS E. LEVOW, Primary Examiner.

H. M. S. SNEED, Assistant Examiner. 

1. A COMPOUND HAVING THE FORMULA 